1. Field of Invention
The present invention relates to a display, especially a display incorporating an array of OLED pixels, or an OLED backlight used in conjunction with an array of LCD pixels, or an array of pixels formed from electronic paper.
2. Description of Related Art
Existing types of display units (whether incorporating cathode ray tubes, liquid-crystal displays or plasma panels) have a region of no display along their perimeter. Thus, when display units of a given type are bolted together to form larger display, these dead-areas are plainly visible, dividing up the resultant screen into a grid, thereby limiting the overall effect of the composite screen.
In the last few years, displays incorporating OLED (Organic Light Emitting Device) material have been developed for use in automotive dashboards, instrument panels and car radios in order to make good use of the known characteristics of good power efficiency, thermal stability and extended lifetime.
A passive matrix display comprises an array of active display elements (pixels), which are addressed by a transparent front plane of electrical tracks and a metal rear plane of electrical tracks. The front and rear planes of tracks are orthogonal to each other and, by switching on one row at a time, display data can be sent to the corresponding column. Switching this row off and switching the next row on with its corresponding column data builds up a continuous picture over the area of the display as each row is cycled on and off, provided that the rate at which the entire display is updated is less than 1/50th of a second. This is a relatively cheap and easy display to make.
An active matrix display utilises transistors as part of each display pixel in a screen. The transistors can be independently controlled, and switch each pixel on or off independently of it's neighbours. This is a more costly alternative to passive addressing, though gives better quality displays when used with LCD technology.